Scylla
et al | method = | site = | pronounce = Sīluh | adjective = Scyllian | planet_numbers = P150, HD 11964 P1, Cetus P4, Aqua P24, 2005 P22, 2005 Cet-2, 2005 Aqu-4 | star_designations = PS 120 c, P4 Ceti c, P18 Aquae c, 9094 c, 81.1 Ac, GJ 9063 Ac, 148123 c | star = | constellation = | lactoph = Aqua | ra = | dec = | distance = 32.850 107.142 1013.64 | planets = Deino Ceto (retracted) Laima (speculative) | semimajor = 0.229354 34.3109 1.111942 1.90748 51.05 stellar radii | semiminor = 0.229164 AU 34.2825 Gm 1.111019 μpc 1.90590 lmin 51.01 stellar radii | periastron = 0.220011 AU 32.9132 Gm 1.066645 μpc 1.82978 lmin 48.97 stellar radii | apastron = 0.238698 AU 35.7087 Gm 1.157239 μpc 1.98519 lmin 53.13 stellar radii | eccentricity = 0.0407368 | orbital_circ = 1.44064 AU 215.517 Gm 6.98442 μpc 11.9814 lmin | orbital_area = 0.16512 AU2 3695.341 Gm2 3.88109 μpc2 11.4212 lmin2 | orbital_period = 37.821515 days 0.10354966 years 3.2677789 121.61 Scyllian rotations | avg_speed = 66.176 41.120 2.1446 ppc/s | max_speed = 67.510 km/s 41.949 mi/s 2.1879 ppc/s | min_speed = 64.814 km/s 40.273 mi/s 2.1005 ppc/s | orbit_direction = Counterclockwise | inclination = 173.40220° (0.21660° to star’s equator) | arg_peri = 154.89674° | node = 250.03001° | long_peri = 44.92675° | separation = 6.982 | moons = 1 | mean_star_size = 2.25498° | max_star_size = 2.35075° | min_star_size = 2.16672° | mean_star_magnitude = –30.930 | max_star_magnitude = –31.021 | min_star_magnitude = –30.844 | mass = 0.9677 307.5520 1.8373 2.0252 | recip_mass = 1218 | classification = Mid-Jupiter | radius = 1.0372 11.267 71.747 2.2139 | circumference = 450.801 Mm 13.9103 npc | surface_area = 1.0758 SJ 126.94 S⊕ 64690 Mm2 61.59 npc2 | volume = 1.1158 VJ 1430.3 V⊕ 1.547 × 106 Mm3 45.45 npc3 | oblateness = 0.05419 | density = 1.150 g/cm3 | gravity = 2.276 g 22.30 m/s2 73.16 ft/s2 688.1 apc/s2 | escape_v = 57.49 km/s 35.72 mi/s 1.863 ppc/s | hill_radius = 0.0149 AU 2.22 Gm 68.6 npc 31 planetary radii | axial_tilt = 45.19° | rot_period = 50.28659 hours 2.101010 day 181.0317 | rot_velocity = 2.574 km/s 1.599 mi/s 83.41 fpc/s | rot_direction = Counterclockwise | magnetic_field = 47 (0.47 ) | mean_temp = 501 (228 , 442 , 901 ) | peri_temp = 511 K (238°C, 461°F, 920°R) | apo_temp = 491 K (218°C, 424°F, 884°R) | bond_albedo = 0.145 | peri_albedo = 0.146 | apo_albedo = 0.145 | appearance = Clarified jovian | scale_height = 17.6 (10.9 , 0.54 ) | pressure = 82.13 (0.8106 , 11.912 , 616.03 ) | composition = 95.8% (H2) 4.1% (He) 0.037% (CO2) 0.012% (CH4) 0.00074% (H2O) 503 ppb (CO) 502 ppb 322 ppb (PCl5) 267 ppb (C8H18) 532 ppt (H2S) 237 ppt (PH3) 12 ppt }} Scylla (often referred as HD 11964 c) is an which orbits the HD 11964, 107 s or 33 s from in the , which is located in the lactoph Aqua. Scylla is a so-called blue Jupiter with no global cloud cover as it lacks chemicals suitable for clouds, although there are few bands of clouds near the equator and the poles. is named after the monster in that lived on one side of a narrow channel of water. Discovery Scylla was discovered on August 7, 2005 by a team of astronomers led by . The team used the mounted on the telescope in to study if this star wobble caused by planets. On that same day, the second planet Deino was also announced. Chronology and designations Scylla is the 142nd exoplanet discovered since Dannaus ( ) was discovered in July 1988. Scylla has a planet number 150. Scylla is the first planet discovered in the HD 11964 system, despite its designation HD 11964 c (although a is not used because the parent star uses this letter to reduce confusion). However, at the time of its discovery, this planet was designated HD 11964 b. Scylla is the fourth planet discovered in and it is the 24th planet discovered in Aqua. It is the 22nd planet discovered in 2005, 2nd in Cetus and 4th in Aqua. For all of the chronologies and planet number, planetary candidates that are speculated to be s are not counted. Scylla has designations PS 120 c, P4 Ceti c, P18 Aquae c, HD 11964 c, HIP 9094 c, Gliese 81.1Ac, GJ 9063 Ac and SAO 148123 c. Orbit and rotation Scylla takes 3.27 megaseconds (37.8 days) to orbit the star at the average distance of 1.112 microparsecs (0.229 astronomical units), which is 59% the average distance between Mercury and the Sun. Scylla orbits in a circular path with an eccentricity of 0.041, which corresponds to ranging distances from 1.067 to 1.157 μpc (0.220 to 0.239 AU). The direction of Scylla’s orbit is counterclockwise, like planets in our solar system. The planet moves in an average speed of 66.18 km/s and it changes from 64.81 to 67.51 km/s during its orbit. It’s speculated inclination is 173° (0.22° to star’s equator). The argument of periastron is 155° counterclockwise from the point of periastron directly facing the observer. The longitude of the node is 250° from the point of reference to Earth. Adding argument of periastron and longitude of the ascensing node yields 45°. Scylla takes 50 hours, 17 minutes, and 12 seconds to rotate once on its axis, which is over two Earth days. The rotation velocity is 2.574 km/s, 1.599 mi/s, 9265 kph, or 5757 mph. This planet rotates in the same direction as its revolution. Scyllian year lasts 122 Scyllian days, compared to Earth year that lasts 366 Earth days. Observing the star When viewing HD 11964 from one of its moons since this planet is a with no solid surface, that sun would appear to be 47 times brighter than the Sun as seen from Earth, corresponding to its apparent magnitude –30.93. The of HD 11964 as seen from Scylla is 2.255°, which is four and a half times the angular diameter of the full moon and sun as seen from Earth, because Scylla orbits nearly four and a half times closer to the star than Earth to the Sun. However that same magnitude and angular diameter of a star change during its planetary orbit because the orbit is not a perfect circle as mentioned above. Physical characteristics Using the speculated inclination, its speculated for Scylla is 0.9677 MJ or 157.51 M⊕. This planet had a 0.1112 MJ or 35.34 M⊕. This planet is classified as Mid-Jupiter. This planet has radius of 71.747 megameters, which is slightly bigger than . Scylla has density 1.15 g/cm3, which is slightly denser than water. Scylla has gravitational force 2.276 times stronger than Earth’s and 0.899 times that of Jupiter’s. The object that is falling to the planet accelerates at 22.30 m/s2 or 73.16 ft/s2. If you weigh 150 lbs on Earth, you would weigh 341 lbs on Scylla. Interior structure Below Scylla’s outer envelope (atmosphere), the weight of all the gases pressing down produce a tremendous pressure. That pressure allow and to condense in the upper mantle despite the higher temperature deeper down. In the lower mantle lies liquid where hydrogen can conduct electricity under even greater pressure heated beyond its critical point. In the lower mantle, the temperature is 11,400 K and a pressure 190 GPa. At the center lies a core of rock and metal with a mass 22 Earth masses, roughly 7.1% the total mass of the planet. The temperature of the core is estimated to be 20,200 K and an estimated pressure 4.2 TPa. Atmosphere Composition Scylla’s atmosphere composes of 99.9% and . Scylla’s composition other than hydrogen and helium is considerably different compared to the four giant solar system planets because this planet orbits much closer to its star. Scylla contains no in the . However, this planet has gases that are not found in our solar system, such as , , , and . Also there are no ice crystals in the atmosphere because it is too hot. Characteristics Scylla contains doesn't have a global cloud cover and this planet appears deep blue, although it has bands of s around 5° north and south of the equator, another bands at 65° north and south of the equator, and significant cloud cover around the poles. These clouds are made of . These cloud bands are shaped by the planet's fast rotation and s. These clouds form from a localized concentrations of PCl5, which are produced by the s between hydrogen chloride and phosphine using s and ionized particles from the parent star as their s. This planet is classified as clarified jovian. The mean temperature of the cloudtop is 501 K (228°C or 442°F). At 1-bar layer, the temperature is 510 K (237°C or 459°F), which is only slightly hotter than the cloudtop. At 0.1-bar layer, is solid and at 1-bar layer, it can melt tin. Because there are no clouds over most of the planet, it may have only a light wind and no storms. Magnetosphere This planet has a strong , one-and-a-half times stronger than . Even though this planet has no clouds, it can still produce s when the stellar activity is high. Moons and rings Scylla has one and no . The moon, designated as Scylla I or HD 11964 c1 is a volcanic moon that orbits close to the planet, at a distance of 122,341 miles or 196,889 kilometers, which is two times closer to the planet than moon to the Earth. This moon has mass 1.27 Lunar masses and has diameter 1,872 miles or 3,013 kilometers, corresponding to its density 6.54 g/cm3. This moon has gravity 0.280 g (2.75 m/s2). If you weigh 150 lbs on Earth, you’ll weigh just 42 lbs on Scylla I, which is the average weight for 8-9 year olds on Earth. The volcanism on moon is caused by the strong s exerted by the parent planet, just like Jupiter exerting a lot of tidal bulges on which causes . Future studies The method will use to study Scylla might be to see what this planet actually looks like. But direct imaging of this planet will be difficult to achieve because this planet orbits real close to its star, only 23% the distance between Earth and the Sun. Maybe looking for transits across the star would be a better idea, but the probability that this planet will transit HD 11964 will be a slim 0.98% chance. The speculated inclination of 173° is almost face-on, which does not allow for transits. Even with the difficulty of direct imaging and low probability of transit, the inclination of Scylla’s orbit can still be determined using from , , or . Determining the inclination is important for determining its true mass. Perhaps in about two decades, direct imaging of this planet can be achieved using the . The direct imaging can then determine the size of this planet. After determining its size, density and gravity will be calculated. Using the density of the planet, astronomers can probe the interior and determine the mass and size of the core. Astronomers will also study the mantle and its temperature of the core using . Using the spectrometer mounted on the ATLAST, it can determine its temperature and chemicals in the atmosphere. Using the same method, the rotation rate can also be determined using s. Using the rotation rate and circumference of the planet (calculated using 2π radius), can be calculated. In orbit around the planet, moons can be detected using the transit across the planet, detecting the wobble of the planet, or even direct imaging. Rings can be detected using just two methods: transit or direct imaging. Category:Clarified jovians Category:Extrasolar planets Category:Mid-Jupiters